A small snip from earlier water profile calculations:
The target was a weakly mineralised profile ("American" style) for a simple 100% Pale Malt "Pale Ale" (or "Bitter"). Nothing radical, I'd even selected a supposedly "balanced" profile that didn't favour Sulphate or Chloride.
And the existing Yorkshire Dales water profile. It actually needs no further additions to match the "Yellow, Balanced" profile in the calculator, "Bru'n Water" (by Martin Brungard), except it could do with the Chloride content being pepped up a little.
I'd recommended adding a little Calcium Chloride to achieve this. I'd also suggested a separate more moderately mineralised profile (using one of Graham Wheeler's profiles ... and one it so happens I could personally vouch for) that would be closer to the OP's author's experiences in Sussex.
But this is the Yorkshire Dales, one of England's most celebrated areas for ... Limestone caves! The water is relatively lightly mineralised
except for the "bicarbonate" content. Over 100mg of bicarbonate in every litre of water. For surface runoff water (it isn't deep aquifer) this level of dissolved bicarbonate is exceptional, but then this is the Yorkshire Dales!
It is completely beyond my wildest imagination (and believe me, my imagination is capable of some seriously wild thinking!) ... to ever think of a scenario where I'd want to add more "bicarbonate" (in the form of baking soda for example) to this water before (or during) brewing with it. Chasing an "ideal" pH at mash time by making small additions of "bicarbonate" to a live mash is perhaps a dafter idea ... if maybe too strong a warning to say the idea would be insane, but insanity awaits anyone trying to attempt it.
There's one thing that wouldn't be a worry ... using calcium carbonate (powdered chalk or limestone). Seems perverse to suggest powdered chalk will be okay when saying bicarbonate won't be? But unless you can pull some pretty extreme stunts, the powdered chalk will
refuse to dissolve and so can't do much harm anyway (or much anything!).
That 104ppm as bicarbonate needs reducing before attempting to brew with this water. In this case I've suggested 0.18ml per litre of 81% Phosphoric Acid ... a typical "American" way of dealing with excess bicarbonate (and dropping the pH too; I was aiming for a mash of about pH5.3). But strong Phosphoric Acid is getting harder to obtain. There are other acids that can be used, including "AMS" available from
The Malt Miller. And any "sparge" water should be acid treated too (to bring it near pH 5.5) to lower the risk of sparging leaching undesirable compounds. The 104ppm bicarbonate can also be expressed as 85ppm "as CaCO
3" should you need it ("Yak! Did I say that?).